Investigating Down Syndrome - Case Study Example

DOWN SYNDROME Of INTRODUCTION The life in South Africa circumstances of persons with intellectual disabilities have changed markedly over the last 10 years (Brown, 2004). Now, with de-institutionalization, improved health care and community participation, individuals with disability enjoy extended life in South Africa opportunities in a range of independent settings. These life in South Africa opportunities present individuals with many more challenging life in South Africa events than experienced by those of previous decades. Their Jives are likely to become more emotionally disconcerting as parents grow older and perhaps die, siblings move out of home and form new families, and they themselves leave regular places of community contact such as schools and workshops. In these new and emerging independent living circumstances, especially in South Africa, individuals with intellectual disability may face situations which place stresses on them that are similar to those found by Rickwood and d'Espaignet (2005) in a study of other young South Africans. The researchers found that when confronted with the stresses of modern life in South Africa young people turned to their friends. Friends appeared to have a role in assisting young people to cope with the stresses, such as family expectations, employment decisions, and the development of self-identity (Rickwood & d'Espaignet, 2005). Brown, Ball, and Powers (2006) also found this to be the case with young women. DISCUSSION The present study of the socio-emotional behaviors of Down syndrome infants in the Strange Situation was designed to extend this work in two ways. First, whereas most research with Down syndrome infants has focused on their acquisition of critical social and emotional responses, our research is concerned with the quality of certain socio-emotional responses that have already been acquired. This is because the quality of early emotional reactions in social contexts-such as their intensity, liability, range, and temporal characteristics-may reflect more significantly the effects of the Down syndrome child's cognitive and physiological impairments. Second, whereas most research in this area has compared Down syndrome and normal children on discrete assessments of behavior (e.g., age of onset, percentage showing a criterion response), we are also interested in comparing the organization of response characteristics between the two samples (cf. Cicchetti & Serafica, 2000). That is, are the interrelations among response parameters similar for Down syndrome and normal infants, even though specific parameters may differ between the two groups Answers to this question should provide further insight into the organized coherence of early development. Earlier research with Down syndrome infants and toddlers has shown that these children reach the same developmental milestones as normal children, but at a delayed pace. Thus, in studies of smiling and laughter to social stimuli (Cicchetti & Sroufe, 2005), eye contact during play with mother (Berger & Cunningham, 2000), fear of a visual loom and visual cliff (Cicchetti & Sroufe, 2006), self-recognition of a mirror image (Mans, Cicchetti, & Sroufe, 2006), selected attachment behaviors (Cytryn, 2004; Serafica & Cicchetti, 2005), symbolic play (Hill & McCune-Nicolich, 2000; Motti, Cicchetti, & Sroufe, 2002), indexes of cognitive functioning, and maternal referencing (Sorce, Emde, & Frank, 2001), the sequence of developmental attainments is similar despite delays in their timing. Viewed from the perspective of the "developmental-difference controversy" (Zigler & Balla, 2001), these findings support the developmental position that normal milestones are achieved by these cognitively retarded children at a delayed rate in comparison with normal. Several of these studies have reported, in fact, that with corrections for mental age, developmental patterns for normal and Down syndrome infants were highly similar. This finding is not entirely consistent across studies, however, because Cicchetti and Sroufe (2006) reported that even with corrections for mental age, Down syndrome infants still showed a diminished intensity of smiling and laughter in comparison with normal. The latter observation is consistent with reports from other investigators. For example, Emde, Katz, and Thorpe (2006) reported that the social smiles of Down syndrome infants were judged to be significantly less intense than those of normal (see also Sorce & Emde, 2001). Similarly, Freudenberg, Driscoll, and Stern (2006) found that the distress cries of Down syndrome infants were rated as less imperative than those of normal infants. On a standard temperament measure, the mothers of Down syndrome infants rated their babies as showing less smiling and laughter than did mothers of normal infants (Rothbart & Hanson, 2002; see also Bridges & Cicchetti, 2001, and Gunn, Berry, & Andrews, 2000). Taken together, these findings indicate that Down syndrome infants may differ from normal infants not only in the rate of developmental acquisitions but also in the quality of their socio-emotional reactions. The primary purpose of this study was to extend this conclusion by comparing the quality of the separation reactions of Down syndrome infants with those of normal infants. We were interested in separation reactions because they are important socio-emotional behaviors that have been little studied in Down syndrome infants thus far and because they develop in both Down syndrome and normal populations by the ages reached by the infants in this study. The characteristics of separation distress that we examined included peak distress intensity, latency to distress onset, rise time from onset until achievement of peak intensity, and recovery time (or soothing) after mother's return. In addition, we examined the range of emotional reactions for each episode of the Strange Situation and emotional liability for the entire procedure. These measures were created from time-sampled ratings of infant facial and vocal expressions throughout the Strange Situation (see Method section). Both facial and vocal expressive modalities were used to provide convergent information about emotional reactions and to ensure that differences between normal and Down syndrome infants could not be attributed to rating errors due to morphological differences in facial expressions between the two groups. The results of this study indicate that whereas Down syndrome and normal infants reacted appropriately to the changes in the social setting caused by the Strange Situation procedure (e.g., distress during separations, soothing during reunions), the Down syndrome infants differed markedly from normal infants in the quality of their emotional responding. Down syndrome infants evinced significantly less intense separation distress, longer onset latency, and a quicker recovery in comparison with normal. They also showed a diminished range of emotional responding during the early episodes and a lower liability of responsiveness throughout the procedure. Although some of these group differences were small in absolute magnitude, they reflected differences in emotional expression that were psychologically significant (e.g., the difference between a sober facial expression and a cry face or between fussing and screaming). Taken together, these qualitative differences in emotionality contribute to an overall characterization of Down syndrome infants as showing subdued emotional reactions and a flattening of socio-emotional variability in comparison with normal, which is consistent with the reports of others (e.g., Cicchetti & Sroufe, 2005, 2006; Emde et al., 2006). Importantly, these differences were apparent whether we compared Down syndrome infants with normal infants of approximately the same age or of a much younger age. In the former case, Down syndrome and normal groups were comparable in chronological growth; in the latter case, the groups were cognitively more comparable, and prior research had led us to expect more similar responsiveness in the latter case. It was clear, however, that the emotional reactions of the Down syndrome infants differed in quality from those of the normal infants at each age and in consistent ways. These findings provide the strongest evidence to date that the quality of socio-emotional responding of Down syndrome infants is not just maturationally delayed but has its own unique aspects. In short, there are certain distinct features of these reactions that are specific to Down syndrome, even with corrections for developmental quotient. At the same time, Down syndrome infants also appear to differ from normal infants in certain aspects of biochemical functioning, and this has provided a second explanation for their affective responses. As discussed by Cicchetti and Sroufe (2006), Down syndrome infants and children have abnormally low levels of plasma dopamine--hydroxylase, an enzyme that is necessary for the conversion of dopamine into norepinephrine (Weinshilboum, Thoa, Johnson, Kopin, & Axelrod, 2000). This suggests deficiencies in the sympathetic nervous system of Down syndrome infants (Axelrod, 2003). Consistent with this, Keele, Richards, Brown, and Marshall (1999) have reported that Down syndrome children excreted significantly less urinary epinephrine than normal children, suggesting a decreased release of epinephrine from the adrenal glands. The adrenal system is known to play an important role in organismic activation in response to stress, fear, or threat. Taken together, these reports support the conclusion of Cicchetti and Sroufe (2006) that "Down's syndrome infants perhaps have a general arousal modulation problem" (p. 342). This conclusion has important implications for the quality of emotional responding of Down syndrome infants, suggesting that they exhibit less intense reactions with longer onset latencies but quicker recoveries than normal infants, because organismic activation is suppressed. These characteristics of distress were also verified in this study. Although most of the latter hypotheses are, of course, consistent with those proposed by the cognitive-appraisal formulation described above, there is one important difference in the predictions offered by the two formulations, which has to do with the speed of recovery from distress. From the cognitive perspective, if the efficiency of information-processing capabilities in Down syndrome infants is impaired, these infants should require a longer period to react emotionally to a change in social circumstances signaling an end to stress (i.e., mother's return) and show a prolonged recovery time. From the arousal-activation perspective, however, recovery should be relatively rapid because organismic activation is more subdued. The results of this study provide greater support for the latter hypothesis. Further support for the importance of such organismic factors is evidence that Down syndrome infants also show longer cry latencies in response to nonsocial stimulus events (such as the painful snap of a rubber band). In such cases, cognitive appraisal processes are less likely to play a major role (recovery from distress was not measured); see Karelitz and Fisichelli (1992) and Fisichelli & Karelitz (1993). It is possible that such organismic factors may also underlie the characteristics of cognitive functioning that we have noted in Down syndrome children. Of course, both cognitive and organismic factors are likely to interact in affecting the socio-emotional responses of Down syndrome infants. The results of this study indicate that such factors contribute to a qualitatively distinct pattern of emotional responding in Down syndrome-normal comparisons. Even so, the organization of these response characteristics was very similar for Down syndrome and normal infants, suggesting that the structure of this socio-emotional response system is similar despite variations in specific response parameters. For both Down syndrome and normal samples, individual differences on measures of distress intensity, latency, and recovery remained highly consistent throughout the Strange Situation, indicating coherent individual patterns of responding. More important, for both samples there were consistent associations between response parameters, with negative associations between distress intensity and onset latency and positive associations between distress intensity and recovery time. That is, for both Down syndrome and normal samples, high-intensity separation reactions had a more rapid onset than mild distress reactions but required a prolonged period for recovery. In addition, for the Down syndrome sample, there was a positive relation between distress intensity and rise time, with high-intensity reactions requiring a longer time to escalate. (We suspect that a similar relation would have been apparent in the normal sample also but for the limited variability of the rise time measure). In explaining these relations, we suggest that these temporal characteristics of emotionality may be related to both the appraisal processes and the energy requirements activating socio-emotional reactions (see Thompson & Lamb, 2003). First, the negative relation between onset latency and distress intensity may reflect how the stimulus event has been appraised by the infant at the moment of its onset. On the one hand, an event that is perceived as highly threatening should elicit prompt as well as strong distress, because both speed and intensity of response function adaptively to either remove a threat or to obtain assistance from others. On the other hand, when the stimulus does not initially seem so compelling, a longer latency may permit continued appraisal of the event and consideration of response options; this is particularly likely when the distress response is mild. Second, the positive relations between distress intensity and both rise time and recovery may reflect the amount of energy required to produce an emotional response. With respect to rise time, highly upset babies should require a longer time to build up to higher peak intensity than mildly distressed infants because of the degree of arousal required for intense distress. For the same reason, highly distressed babies should also require a longer time to settle down afterward. Thus, despite group differences on specific measures of distress intensity, latency, and recovery, Down syndrome and normal infants (of both ages) exhibited very similar patterns of interrelations among these response parameters. In recent work, similar measures of emotional responding of premature infants have been found to be organized in a similar manner (see Frodi & Thompson,). Taken together, these findings suggest that the structure of socio-emotional response systems is consistent in these normal and atypical populations, possibly because they are based in underlying physiological processes related to self-regulation. Facts and Figures Till date, the prevalence of Down syndrome in African populations is not clearly known. In a study on disability in children between 2 and 9 years of age at present being undertaken in a rural population in the Eastern Transvaal, South Africa, only two children out of a total of 4168 screened have been recorded to date with Down syndrome (J G R Kromberg, personal communication). Given the incidences of Down syndrome previously recorded, and the above minimum recorded prevalence of 1 in 2084 children, this certainly indicates a significant mortality of Down syndrome infants and children between birth and 2 years of age (Christianson 1996, PP. 89-90). It is a well known fact that the chances of bearing an infant with Down syndrome increases with the advancing maternal age. It has been reported that only 20-7% of the mothers in his series were 35 years of age or older (Adeyokunnu). In various South African studies, AMA was documented in 52%, 56-2%, and 55% of the mothers of Down syndrome infants. Around 60% of the Down syndrome infants born were the fourth or higher in the birth order (Christianson et. al) and this to be the situation in 76% of his cases (Adeyokunnu). CONCLUSION This conclusion is further supported by the results of the correlations between emotion and attachment variables in Down syndrome and normal samples. For both groups, distress intensity was positively correlated with contact maintenance and negatively correlated with distance interaction directed to mother during the reunion episodes. Such a finding is not surprising, because under most circumstances infants who are highly upset are likely to seek comfort in close contact with a caregiver. However, the consistency of this association in both Down syndrome and normal samples indicates that despite group differences in distress intensity, distress serves the same functions in the baby's attachment behaviors. That is, emotion may drive certain attachment behaviors in a consistent manner for both groups of infants. The one important difference to emerge concerns the stronger association between distress intensity and mother-directed resistance in the Down syndrome sample and suggests that high-intensity distress may have an added (and somewhat more negative) effect on the attachment behaviors of the ordinarily more subdued Down syndrome infants. The consistency between these groups, though, was most impressive, further attesting to the coherent organization underlying these socio-emotional response systems. REFERENCES 1. Axelrod, J. (2003, June). Neurotransmitters. Scientific American, 230, 58-71. 2. Berger, J. Cunningham, C. C. (2000). The development of eye contact between mothers and normal versus Down's syndrome infants. Developmental Psychology, 17, 678-689. 3. Bridges, F. A. Cicchetti, D. (2001). Mothers' ratings of the temperament characteristics of Down syndrome infants. Developmental Psychology, 18, 238-244. 4. Brown, R. I. (1995). Social life in South Africa, dating and marriage. In L. Nadel & D. Rosenthal (Eds.), Down syndrome: Living and learning in the community (pp. 43-49). New York: Wiley-Liss. 5. Brown, W. Ball, K. Powers, J. (1998). is life in South Africa a party for young women. ACHPER Healthy Life in South Africa style Journal, 45(3), 21-26. 6. Christianson AL, Kromberg JGR, Viljoen E. 1995. The clinical features of black African neonates with Down syndrome. E Afr Med J.; 72:306-10. 7. Christianson, Arnold L. 1996. Down syndrome in sub-Saharan Africa. Jf Med Genet; 33:89-92 8. Cicchetti, D. Mans, L. (in press). Stages, sequences, and structures in the organization of cognitive development in Down syndrome infants. In I. Uzgiris & J. McV.Hunt (Eds.), Research with scales of psychological development in infancy. Urbana: University of Illinois Press. 9. Cicchetti, D. Sroufe, L. A. (2005). The relationship between affective and cognitive development in Down's syndrome infants. Child Development, 47, 920-929. 10. Cicchetti, D. Sroufe, L. A. (2006). An organizational view of affect: Illustration from the study of Down's syndrome infants. In M.Lewis & L.Rosenblum (Eds.), The development of affect (pp. 309-350). New York: Plenum Press. 11. Cytryn, L. (2004). Studies of behavior in children with Down's syndrome. In E. J.Anthony (Eds.), Explorations in child psychiatry (pp. 271-275). New York: Plenum Press. 12. Emde, R. N. Katz, E. L. Thorpe, J. K. (2006). Emotional expression in infancy: II. Early deviations in Down's syndrome. In M.Lewis & L.Rosenblum (Eds.). The development of affect (pp. 351-360). New York: Plenum Press. 13. Field, T. Sostek, A. Goldberg, S. Shuman, H. (Eds.). (1999). Infants born at risk. New York: Spectrum. 14. Fisichelli, V. R. Karelitz, S. (1993). The cry latencies of normal infants and those with brain damage. Journal of Pediatrics, 62, 724-734. 15. Freudenberg, R. P. Driscoll, J. W. Stern, G. S. (2006). Reactions of adult humans to cries of normal and abnormal infants. Infant Behavior and Development, 1, 224-227. 16. Frodi, A. Thompson, R. A. (in press). Infants' affective responses in the strange situation: Effects of prematurity and of quality of attachment. Child Development, 56. 17. Gunn, P. Berry, P. (1995). Down syndrome temperament and maternal response to child behavior. Developmental Psychology, 21, 842-847. 18. Gunn, P., Berry, P. Andrews, R. J. (2000). The temperament of Down's syndrome infants: A research note. Journal of Child Psychology and Psychiatry, 22, 189-194. 19. Hill, P. M. McCune-Nicolich, L. (2000). Pretend play and patterns of cognition in Down's syndrome children. Child Development, 52, 611-617. 20. Karelitz, S. Fisichelli, V. R. (1992). The cry thresholds of normal infants and those with brain damage. Journal of Pediatrics, 61, 679-685. 21. Keele, D. K. Richards, C., Brown, J. Marshall, J. (1999). Catecholamine metabolism in Down's syndrome. American Journal of Mental Deficiency, 74, 125-129. 22. Mans, L., Cicchetti, D. Sroufe, L. A. (2006). Mirror reactions of Down's syndrome infants and toddlers: Cognitive underpinnings of self-recognition. Child Development, 49, 1247-1250. 23. Motti, F., Cicchetti, D. Sroufe, L. A. (2002). From infant affect expression to symbolic play: The coherence of development in Down's syndrome children. Child Development, 54, 1168-1175. 24. Rickwood, D. d'Espaignet, E. T. (2005). Psychological distress among older adolescents and young adults in Australia. Australian and New Zealand Journal of Public Health, 20, 83-86. 25. Rothbart, M. K. Hanson, M. J. (2002). A caregiver report comparison of temperamental characteristics of Down's syndrome and normal infants. Developmental Psychology, 19, 766-769. 26. Serafica, F. C. Cicchetti, D. (2005). Down's syndrome children in a Strange Situation: Attachment and exploration behaviors. Merrill-Palmer Quarterly, 22, 137-150. 27. Sorce, J. F. Emde, R. N. (2001). The meaning of infant emotional expressions: Regularities in care giving responses in normal and Down's syndrome infants. Journal of Child Psychology and Psychiatry, 23, 145-158. 28. Sorce, J. F., Emde, R. N. Frank, M. (2001). Maternal referencing in normal and Down's syndrome infants: A longitudinal analysis. In R. N.Emde. R.Harmon (Eds.). The development of attachment and affiliative systems (pp. 281-292). New York: Plenum Press. 29. Sroufe, L. A. Waters, E. (2005). The ontogenesis of smiling and laughter: A perspective on the organization of development in infancy. Psychological Review, 83, 173-189. 30. Thompson, R. A. Lamb, M. E. (2002a). Individual differences in dimensions of socioemotional development in infancy. In R.Plutchik & H.Kellerman (Eds.), Emotion: Theory, research and experience. Emotions in early development (Vol. 2, (pp. 87-114). New York: Academic Press. 31. Thompson, R. A. Lamb, M. E. (2002b). Security of attachment and stranger sociability in infancy. Developmental Psychology, 19, 184-191. 32. Thompson, R. A. Lamb, M. E. (2003). Assessing qualitative dimensions of emotional responsiveness in infants: Separation reactions in the Strange Situation. Infant Behavior and Development, 7, 423-445. 33. Weinshilboum, R. M. Thoa, N. B. Johnson, D. G. Kopin, I. J. Axelrod, J. (2000). Proportional release of norepinephrine and dopamine--hydroxylase from sympathetic nerves. Science, 174, 1349-1351. 34. Zigler, E. Balla, D. (2001). Mental retardation: The developmental-difference controversy. Hillsdale, NJ: Erlbaum. Appendix A Source: [Online]. http://en.wikipedia.org/wiki/Down_syndrome Appendix B Down Syndrome Karyotype Source: [Online]. http://en.wikipedia.org/wiki/Down_syndrome Appendix C Age of Children Source: http://nacd.org/more_information/efficacy_of_the_nacd_program.pdf Read More